JP2016116110A - Communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication apparatus capable of continuing the operation even when the electric power supplied from a communication line is lowered.SOLUTION: The communication apparatus operates on the electric power which is supplied from a communication line. The communication apparatus includes a controller that, when the electric power supplied from the communication line is detected to have got lowered to a predetermined range, controls the communication apparatus to start at least one of a reduction operation including partial discontinuation of the functions of the communication apparatus and performance reduction of the functions of the communication apparatus.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a communication device.

Power over Ethernet (registered trademark) (P
oE). PoE is a technology for supplying power using an Ethernet communication cable (hereinafter referred to as a Local Area Network (LAN) cable). Standards related to PoE include IEEE 802.3af and IEEE 802.3at.

  One of communication apparatuses (electronic devices) to which PoE is applied is a base station apparatus called a femto base station. A LAN cable (referred to as a PoE line) is connected to the femto base station, and electric power supplied from the PoE line is supplied to each part in the femto base station to execute various functions as the base station.

JP 2010-63000 A Special table 2012-518820 gazette

  With the recent enhancement of femto base station functionality, the power supplied by one PoE line may be insufficient. In this case, power is supplied to the femto base station via a plurality of PoE lines.

  However, when power is not supplied to any one of a plurality of PoE lines due to a line failure or an upstream device failure, the entire femto base station has been suspended.

  An object of one embodiment of the present invention is to provide a communication device that can continue operation even when power supplied from a communication line decreases.

  One embodiment of the present invention is a communication device that operates with power supplied from a communication line. The communication device includes at least one of a partial stop of the function of the communication device and a decrease in performance of the function when it is detected that the power supplied from the communication line has fallen to a predetermined range. It includes a control device that starts the degenerate operation of the device.

  According to one embodiment of the present invention, operation can be continued even when power supplied from a communication line is reduced.

FIG. 1 shows a hardware configuration example of a femto base station. FIG. 2 is a diagram schematically illustrating functions of the femto base station illustrated in FIG. FIG. 3 is a graph for explaining the relationship between the PoE line abnormality and the voltage. FIG. 4 shows a calculation formula for the required capacity of the capacitor and a table showing an example of the required capacity calculation. FIG. 5 is a table showing a pattern example of the receivable power of the femto base station according to the PoE line class and the PoE line state. FIG. 6 shows an example of the data structure of the combination table for degenerate operation. FIG. 7 is a diagram illustrating the relationship between the number of connected UEs indicating the number of wireless terminals connected to the femto base station and the operating state of the CPU. FIG. 8 is a diagram illustrating a relationship between the maximum path loss amount of the wireless terminal currently connected to the femto base station and the transmission power. FIG. 9 shows an example of the data structure of the combination table for degenerate operation. FIG. 10 is a flowchart illustrating a processing example of the processor.

  Hereinafter, embodiments will be described with reference to the drawings. The configuration of the embodiment is an exemplification, and is not limited to the configuration of the embodiment.

  In the embodiment described below, a communication device that operates with electric power supplied from a communication line, and starts communication operation when it is detected that the electric power supplied from the communication line has fallen to a predetermined range. The apparatus will be described.

The “communication device” includes a base station device and an electronic device having a communication function other than the base station device. The “base station device” is, for example, a radio base station of a mobile phone, regardless of the type of radio communication standard (radio communication scheme) that the radio base station complies with. Examples of wireless communication standards include Global System for Mobile communications (GSM (registered trademark)), Wideband Code Division Multiple Access (W-CDMA (also called Universal Mobile Telecommunications System (UMTS))), CDMA2000, Long Term Evolution (LTE). ), LTE-Adva
The second to fourth generation wireless communication standards such as nced. However, the wireless communication standard is not limited to these.

Further, the “base station apparatus” is not limited by the size of the cell formed by the base station. The “base station” includes, for example, a femto base station, a pico cell base station, a small cell base station, and other base stations. In addition, the “base station device” is not only a wireless communication standard for mobile phones, but also a wireless communication that conforms to other wireless communication standards such as Wi-Fi, wireless LAN (IEEE802.11 series), or Bluetooth (registered trademark). Also includes an access point device. In the embodiment, an example in which a femto base station is applied as a “communication device” will be described.

<Configuration of femto base station>
FIG. 1 shows a hardware configuration example of a femto base station. In FIG. 1, the femto base station 10 includes a processor 11, a dynamic random access memory (DRAM) memory 12, a flash memory 13, and a hard disk drive (HDD) 14 connected to the processor 11.

Further, the femto base station 10 includes an LTE RF (Radio Frequency) unit 15 (LTE (
# 0)) and RF unit 16 (LTE (# 1)), Wi-Fi RF unit 17 (Wi-Fi (# 0)), RF unit 18 (Wi-Fi (# 1)) and RF unit 19 (Wi-Fi (# 2)). Each of the RF units 15 to 19 is connected to a processor. LTE is an example of a “first wireless communication method”, and Wi-Fi is an example of a “second wireless communication method”.

The RF unit 15 is connected to the transmission / reception antenna 20, and the RF unit 16 is connected to the transmission / reception antenna 21. The RF unit 17 is connected to the transmission / reception antenna 22, the RF unit 18 is connected to the transmission / reception antenna 23, and the RF unit 19 is connected to the transmission / reception antenna 24.

  As described above, the femto base station 10 performs radio communication with the radio terminal (User Equipment (UE)) 40 using two different radio communication standards, LTE and Wi-Fi. The wireless terminal 40 supports at least one of LTE and Wi-Fi. The wireless terminal 40 is an example of a “terminal”.

  Further, the femto base station 10 includes an external interface (external INF) 25 and a power supply unit 26. The external INF 25 is an interface circuit that accommodates a plurality of LAN lines (LAN lines # 0 to #n (n is an integer of 1 or more)), and is connected to the core network 30 via the LAN lines # 0 to #n. Yes. The LAN lines # 0 to #n are examples of “PoE line” and “communication line”.

  The external INF 25 manages packet transmission / reception processing with the core network 30. As the external INF 25, for example, a LAN card or a network interface card (NIC) can be applied.

  The power supply unit 26 receives power supplied from the LAN lines # 0 to #n, and supplies operating power to a power supply destination in the femto base station 10 via a power supply line (not shown). The supply destination includes the processor 11, DRAM memory 12, flash memory 13, HDD 14, RF units 15 to 19, and transmission / reception antennas 20 to 24. Further, the power supply destination may be a peripheral device connected to the femto base station 10 via an interface (not shown). Further, the power supply unit 26 monitors the power supply state from each of the LAN lines # 0 to #n.

  Each of the RF units 15 to 19 is formed of a circuit group that handles radio signals (RF signals). For example, each of the RF units 15 to 19 includes a DA converter, an up converter, a power amplifier, and a duplexer as a circuit group for the downlink. The DA converter converts a digital baseband signal supplied from the processor into an analog signal. The up-converter up-converts an analog signal into a radio frequency (RF) signal (radio signal). The power amplifier amplifies the radio signal. The duplexer connects the amplified radio signal to a transmission / reception antenna. Each of the transmission / reception antennas 20 to 24 transmits a radio signal. Each of the RF units 15 to 19 includes a low noise amplifier, a down converter, and an AD converter as an uplink circuit group. Radio signals received by each of the transmission / reception antennas 20 to 24 are connected to a low noise amplifier via a duplexer. The low noise amplifier amplifies a radio signal with low noise. The down converter down-converts the radio signal amplified with low noise into an analog signal. The AD converter converts the analog signal into a digital baseband signal and sends it to the processor 11.

  The DRAM memory 12 is used as a work area (main storage device: main memory) of the processor. Each of the flash memory 13 and the HDD 14 stores a program executed by the processor and data used when the program is executed.

The DRAM memory 12 is an example of a random access memory (RAM), and may be an SRAM (Static RAM). The RAM is an example of a volatile storage medium (volatile memory). Each of the flash memory 13 and the HDD 14 is an example of an auxiliary storage device. The auxiliary storage device may be a nonvolatile storage medium (nonvolatile memory) other than the flash memory 13 and the HDD 14. Non-volatile storage media include Read Only Memory (ROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Solid State Drive (SSD), and the like. In FIG. 1, an example including the flash memory 13 and the HDD 14 is shown, but providing both is not an essential requirement, and either one may be omitted. The volatile storage medium and the non-volatile storage medium described above are examples of “computer-readable storage medium”, “storage device”, and “memory”.

The processor 11 is, for example, a central processing unit (CPU), a digital signal processor (DSP), or a combination thereof. The processor 11 performs various processes by loading a program stored in at least one of the flash memory 13 and the HDD 14 into the DRAM memory 12 and executing it.

  For example, the processor 11 performs baseband processing. The baseband processing includes processing for encoding a packet (data) from the external INF 25, digitally modulating it into a digital baseband signal, and sending it to one of the corresponding RF units 15-19. The baseband processing includes processing for obtaining data by demodulating and decoding digital baseband signals from the RF units 15 to 19. Further, the processor 11 performs processing for generating a packet including data and sending the packet to the external INF 25. In addition, the processor 11 performs call processing and maintenance / management / monitoring (OAM) processing of the wireless terminal 40.

  Further, when the processor 11 detects that the power supplied from the LAN lines # 0 to #n (PoE cable) has fallen to a predetermined range by the interrupt notification from the power supply unit 26, the degeneration of the femto base station 10 is performed. Start operation. In other words, when the power supplied from the LAN lines # 0 to #n is in a normal range, the femto base station 10 operates in the normal mode, and when the power decreases to a predetermined range below the normal range, Operates in the reduced operation mode.

The processor 11 may be a combination of a CPU, a DSP, and a combination thereof and an integrated circuit (IC). The integrated circuit is IC, Large Scale Integration (
LSI), Application Specific Integrated Circuit (ASIC), and Programmable Logic Device (PLD). The PLD includes, for example, a field programmable gate array (FPGA). Further, the processing performed by the processor 11 may be performed by hardware logic formed by one or more integrated circuits. In other words, the processor 11 may be a device that performs software processing using a general-purpose processor such as a CPU or DSP, or may be a device formed by a dedicated hardware circuit. The processor 11 is an example of a “control circuit” or “controller”.

  FIG. 2 is a diagram schematically illustrating functions of the femto base station 10 illustrated in FIG. In FIG. 2, PoE line # 0 to PoE line #n are the LAN lines # 0 to #n shown in FIG. 1, and are connected to the power supply unit 26. The power supply unit 26 has the following configuration for each of the PoE lines # 0 to PoE line #n. The PoE line # 0 will be described as an example. The PoE line # 0 is connected to the DCDC converter 261 and is converted into a voltage for operating the femto base station 10. The DCDC converter 261 is connected to the power supply circuit 264. The power supply circuit 264 is connected to the DCDC converter 261 corresponding to each PoE line, and supplies power to the power supply destination of the femto base station 10.

  The PoE line # 0 in the previous stage of the DCDC converter 261 is provided with a capacitor 262 for protection against instantaneous interruption. Capacitor 262 avoids a sudden drop in voltage when a momentary abnormality (instant interruption) occurs in PoE line # 0. The voltage of the PoE line # 0 is monitored by the power supply monitoring circuit 263.

The power monitoring circuit 263 monitors the voltage supplied from the corresponding PoE line. FIG. 3 is a graph for explaining the relationship between the PoE line abnormality and the voltage. In FIG. 3, if the power supply from the PoE line is normal, a constant voltage (PoE normal supply voltage) is observed. On the other hand, it is assumed that the power supply from the PoE line # 0 is stopped by the corresponding PoE line (for example, the PoE line # 0 in FIG. 2 is abnormal: see <1> in FIG. 2).

  In this case, the voltage is not lowered suddenly by the capacitor 262 but gradually falls (see FIG. 3). Note that the slope of the voltage drop depends on the capacitance of the capacitor 262. Unless the power supply of PoE line # 0 is restored, the voltage further decreases below the lower limit value of PoE normal supply voltage (the lower limit value at which power supply is normal), and exceeds the predetermined power monitoring threshold value. To do. Then, the power supply monitoring circuit 263 detects a power supply abnormality (FIG. 2 <2>), and sends an interrupt notification to the processor 11 to start the degenerate operation of the femto base station 10 (FIG. 2 <3>). ).

  As shown in FIG. 3, the femto base station 10 has a device operation limit voltage. When the voltage drops below the device operation limit voltage, the femto base station 10 cannot maintain the operating state and stops all functions. It becomes a state. For this reason, the transition (shift) to the degenerate operation is performed when the voltage is in a range between the power supply monitoring threshold and the device operation limit voltage.

  Note that the time from the detection of the voltage drop exceeding the voltage monitoring threshold in the power supply monitoring circuit 263 to the transition to the degenerate operation varies slightly depending on the type of CPU included in the processor 11 and the like. However, the transition can be made within a few ms. A capacitor 262 is arranged so that the power supply does not cut off momentarily during such mode switching.

FIG. 4 is an explanatory diagram of the capacitance of the capacitor. The capacitance (Cin) of the capacitor can be calculated using the following calculation formula.
Cin = 2 × Win × t / (Vin−Vout) ²
However, “Win” is the power consumption (for PoE1 line) of the femto base station 10 before the degeneration operation, “t” is the transition time to the degeneration operation, and “Vin” is the power monitoring threshold value. “Vout
"Is a device operation limit voltage. FIG. 4 shows an example of calculation of the required capacity of the capacitor 262.

  Upon receiving the interrupt notification, the processor 11 calculates the amount of power that can be used by the femto base station 10 based on the number of PoE lines to which normal power supply is performed. In the PoE standards IEEE 802.3af and IEEE 802.3at, the standards are classified for each power that can be supplied by a power supply equipment (PSE, Power Sourcing Equipment) in one line. For each class, the maximum power that can be received by the power receiving device (PD) is determined. Currently, there are five classes, class 0 to class 4. The maximum power that can be received is 13.0 [W] for class 0, 3.84 [W] for class 1, 6.49 [W] for class 2, 12.95 [W] for class 3, and 4 for class 4 It is 25.5 [W]. For this reason, the processor 11 can calculate electric energy with the following structures, for example.

  That is, in the predetermined storage area of the flash memory 13 or the HDD 14, information indicating the power that can be received according to the classes of the PoE line # 0 to PoE line #n is stored in advance. As the receivable power, the maximum power value that can be received in each class may be used, or a predetermined value smaller than the maximum power value may be used.

  The processor 11 manages the power supply state (normal, abnormal (failure)) from each of the PoE line # 0 to PoE line #n. In management, for example, the processor 11 can determine that the power supply state of the PoE line that has received the interrupt notification is abnormal, and can determine that the power supply state of the PoE line that has not received the interrupt notification is normal. Alternatively, when receiving an interrupt notification from a certain power supply monitoring circuit 263, the processor 11 may inquire the remaining power supply monitoring circuit 263 about normality / abnormality of the power supply state.

  When the processor 11 confirms the power supply status (normal / abnormal) of each PoE line # 0 to PoE line #n, the processor 11 can receive power from the normal PoE line using information on the receivable power of each PoE line. Is calculated as power that can be received at the femto base station 10 and stored in the DRAM memory 12.

  The processor 11 reads the degenerate operation combination table (details will be described later) stored in the flash memory 13 into the DRAM memory 12 (<4> in FIG. 2). Subsequently, the processor 11 determines the operation content in the reduced operation mode, that is, the content of the reduced operation, based on the receivable power and the combination table (<5> in FIG. 2).

  In the example illustrated in FIG. 2, an antenna 51, an antenna 52, a functional unit (functional block) 53, and a functional unit (functional block) 54 are illustrated. The antenna 51 is the LTE RF unit 15 and the transmission / reception antenna 20 shown in FIG. The antenna 52 is the LTE RF unit 16 and the transmission / reception antenna 21 shown in FIG. The functional unit 53 (functional unit # 0) is the Wi-Fi RF unit 17 to RF unit 19 and the transmission / reception antenna 22 to the transmission / reception antenna 24 shown in FIG. The functional unit 54 (functional unit #n) is the HDD 14 shown in FIG.

  The processor 11 determines, for example, that the antenna 52 (the RF unit 16 and the transmission / reception antenna 21) and the functional unit 54 (HDD 14) are stopped as the contents of the reduced operation in the reduced operation mode, and performs the reduced operation (in the reduced operation mode). Operation) (see <6> in FIG. 2). That is, for example, the processor 11 supplies a control signal to the power supply circuit 264 and stops the power supply from the power supply circuit 264 to the antenna 52 and the function unit 54. Or the processor 11 will be in the state which does not use the antenna 52 and the function part 54 (it does not operate).

  By such degenerate operation, that is, by stopping or not using the power supply of the antenna 52 and the functional unit 54, the power consumption of the femto base station 10 is reduced, and the power consumption amount in the femto base station 10 is within the range of power that can be received. It will fit. Therefore, the femto base station 10 can continue (maintain) the operating state of the femto base station 10 even if the power supplied from the PoE line decreases.

<Receivable power>
Next, the power that can be received in the femto base station 10 will be described. FIG. 5 is a table showing a pattern example of the receivable power of the femto base station according to the PoE line class and the PoE line state. In FIG. 5, as an example, it is assumed that there are three PoE lines, PoE line # 0, PoE line # 1, and PoE line # 2, (n = 2). Further, FIG. 5 shows five pattern examples in which the femto base station 10 can receive power.

  In the first pattern (NO.1), the PoE line # 0, the PoE line # 1, and the PoE line # 2 are all class 4 (receivable power: 25.5 [W]), and each PoE line Shows the case where is normal. In this case, the total value 76.5 [W] of the receivable power becomes the receivable power of the femto base station 10.

  In the second pattern (NO.2), PoE line # 0 and PoE line # 1 are class 4 (receivable power: 25.5 [W]), and PoE line # 2 is class 0 (receivable power). : 13 [W]) and each PoE line is normal. In this case, 64 [W], which is the total value of the receivable power, becomes the receivable power of the femto base station 10.

In the third pattern (NO.3), PoE line # 0 and PoE line # 2 are class 4 (receivable power: 25.5 [W]), and PoE line # 1 is abnormal (failure). Show the case. In this case, 51 [W], which is the total value of the receivable power, is the receivable power of the femto base station 10.

  In the fourth pattern (NO.4), PoE line # 0 is class 4 (power that can be received: 25.5 [W]) and normal, PoE line # 1 is abnormal (failure), and PoE. A case where line # 2 is class 0 (receivable power: 13 [W]) is shown. In this case, 38.5 [W], which is the total value of the receivable power, becomes the receivable power of the femto base station 10.

  In the fifth pattern (NO. 5), the PoE line # 0 and the PoE line # 2 are class 0 (receivable power: 13 [W]) and normal, and the PoE line # 1 is abnormal (failure). Show the case. In this case, 26 [W], which is the total value of the receivable power, becomes the receivable power of the femto base station 10.

  The above-described power that can be received can be handled as power that can be consumed by the femto base station 10, that is, power that can be consumed.

<Degenerate operation of function (restriction of function)>
Next, the reduced operation of functions performed in the reduced operation mode will be described. “Functional degeneration operation” means maintaining the operating state (operation) of the femto base station 10 by at least one of partial stoppage of the function of the femto base station 10 (communication device) and performance degradation of the function. It is. “Degenerate operation” is also called “degenerate operation”. However, the partial stop of the function and the performance degradation of the function are not strictly distinguished. “Degenerate operation of function” is performed by stopping power supply or reducing the amount of power supply to a component or part that exhibits a function, or by not using a component or part that performs a function. In addition, “degenerate operation of the function” takes into account the receivable power (consumable power) of the femto base station 10 so that the power consumption during the degenerate operation is within the range of receivable power (consumable power). The contents of the degenerate operation may be determined.

Examples of the reduced function operation include the following. However, the following is a list of examples and is not limited thereto.
(A) Reduction of radio transmission power Radio transmission power for transmitting a radio signal from an antenna (hereinafter also referred to as “transmission power”) is reduced. For example, when the transmission power in the normal time is 100 [mW], the transmission power is set to a value smaller than 100 [mV] in the degenerate operation. For example, the wireless transmission power is 50 [m
W]. A plurality of transmission power values during the degenerate operation may be prepared according to the power that can be received. For example, when there are three PoE lines of the same class and the transmission power when all of these are normal is 100 [mV], the transmission power is 50 when the number of PoE lines with abnormal power supply is one. Set to [mW], and when there are two PoE lines with abnormal power supply, the transmission power is set to 10 [mW]. The power consumption can be reduced by reducing the transmission power.

(B) Reduction of the number of active antennas The femto base station 10 performs communication related to LTE with the radio terminal 40 using Multiple Input Multiple Output (MIMO), for example, using a plurality of transmission antennas. In this case, in the degenerate operation, communication with the wireless terminal 40 is performed by single input and single output (SISO). For example, it is assumed that MIMO communication is performed using the RF unit 15 and the transmission / reception antenna 20, and the RF unit 16 and the transmission / reception antenna 21 illustrated in FIG. 1. In this case, in the degenerate operation, one of the RF unit 15 and the transmission / reception antenna 20, the RF unit 16 and the transmission / reception antenna 21 is stopped, or power supply is stopped, and communication is performed using SISO. Power consumption can be reduced by using the RF unit and antenna or by stopping power supply.

  However, when a plurality of antennas are used, it is not an essential requirement to perform MIMO communication. In the above example, the reduction in the number of active antennas in communication related to LTE is exemplified, but the reduction in the number of antennas for Wi-Fi may be implemented.

(C) Reduction of Maximum Number of Simultaneously Connected Users In the degenerate operation, the number of wireless terminals 40 (maximum number of simultaneously connected users) that can be connected in parallel to the femto base station 10 is reduced from the number at the normal time. By reducing the maximum number of simultaneous users, the following operations are performed. For example, the operation clock of the CPU included in the processor 11 is lowered. For example, the operation clock can be made lower than the operation clock in the normal mode by changing the operation mode of the CPU to the low power consumption mode. Alternatively, when the CPU included in the processor 11 has a multi-core configuration, the operation is normally performed using two or more cores (for example, two cores), while the degenerate operation is used for the operation. Reduce the number of cores (for example, set the number of cores to 1). Power consumption can be reduced by reducing the operating clock and the number of operating cores.

(D) Stop of functional unit (functional block) The femto base station 10 can be regarded as a set of a plurality of functional units (functional blocks). In normal operation, all the function units are used, whereas in the degenerate operation, a function having a low priority among a plurality of function units is stopped. For example, the femto base station 10 illustrated in FIG. 1 has a function as a Wi-Fi base station (access point) in addition to a function as an LTE base station (eNB). In addition to the flash memory 13, the femto base station 10 includes an HDD 14 as an auxiliary storage device.

  In this case, for example, the priority order of LTE is set higher than Wi-Fi, and the priority order of flash memory 13 is set higher than HDD 14. As a result, LTE and Wi-Fi, and the flash memory 13 and HDD 14 are used in the normal state, whereas at least one of Wi-Fi and HDD 14 is stopped in the degenerate operation. The power consumption can be reduced by stopping the Wi-Fi RF unit and antenna and the HDD 14 (power supply is stopped or not used). However, the type of the function unit to be stopped is not limited to Wi-Fi or HDD. For example, the LTE or flash memory 13 may be stopped.

  In the degeneration operation mode, for example, the power consumption of the femto base station 10 can be reduced by the degeneration operation as described in the above (a) to (d). Accordingly, the operation of the femto base station 10 can be continued within the range of power that can be received, that is, power that can be consumed by the femto base station 10.

  For example, information indicating the type of degeneration operation as described above (a) to (d) and the power consumption reduction amount corresponding to each degeneration operation is previously stored in the nonvolatile memory (flash memory 13). Can do. Then, the processor 11 selects the type of degenerate operation so that the power consumption reduction amount becomes larger than the insufficient power amount obtained from the receivable power. In this way, the contents (scale and combination) of the reduced operation performed in the reduced operation mode can be dynamically determined and determined.

<Combination table for reduced operations>
In addition, a degenerate operation combination table that stores consumable power according to the state (normal / abnormal) of each PoE line and information indicating the contents (scale and combination) of degenerate operation corresponding to the consumable power is stored in advance in a nonvolatile manner. Can be stored in the memory (flash memory 13 shown in FIG. 1). As a result, the calculation of the insufficient power amount and the storage of the power consumption reduction amount as described above can be omitted.

  FIG. 6 shows an example of the data structure of the combination table for degenerate operation. In FIG. 6, the combination table stores combinations of statuses (states) for PoE line # 0 to PoE line # 2 (example of n = 2) and consumable power [W] in each combination. Consumable power is power that can be received by the femto base station 10 described above.

  Further, the combination table stores information indicating the operation state corresponding to the power that can be consumed for each function to be degenerated in the femto base station 10 as the device operation state. In the example shown in FIG. 5, the RF operation power (wireless transmission power), the number of operating cores of the CPU, the operating clock speed of the CPU, the number of operating antennas, and the functional blocks (Wi-Fi and HDD) are the functions to be degenerated. Illustrated.

The RF transmission power corresponds to the function limitation (degenerate operation) described in (a) above. In the example of FIG. 5, transmission power values of 100 [mV], 50 [mV], and 10 [mV] are prepared. When the consumable power is 76.5 [W] (normal mode) and 51 [W], the transmission power is 100 [
mV]. On the other hand, the transmission power is set to 10 [mV] when the consumable power is 25.5 [W].

  For example, “single (1)” and “dual (2)” are prepared as the number of CPU operating cores. When the consumable power is 76.5 [W] (normal mode), the CPU operates in “dual”, whereas when the consumable power is 51 [W] and 25.5 [W], “ The CPU operates in “single”.

As an example of the CPU operation clock, 600 MHz, 800 MHz, and 1G
Hz is prepared. When the consumable power is 76.5 [W] (normal mode), the operation clock is set to 1 GHz. On the other hand, when the power consumption is 51 [W], the operation clock is 800 MHz, and when the power consumption is 25.5 [W], the operation clock is 600 MHz.

  As an example of the number of LTE operating antennas, one and two are prepared. When the consumable power is 76.5 [W] (normal mode), it is operated with two operating antennas, whereas when the consumable power is 51 [W] and 25.5 [W], 1 is used. Operated with a book antenna.

  As the functional unit, as illustrated in FIG. 2, Wi-Fi and HDD 14 are targets. When the consumable power is 76.5 [W] (normal mode), both the Wi-Fi and the HDD 14 are set in the operating state. In contrast, when the consumable power is 51 [W], the operation of the HDD 14 is stopped, and when it is 25.5 [W], the operation of both the Wi-Fi and the HDD 14 is stopped.

  As in the combination table illustrated in FIG. 5, by using the power that can be received based on the PoE class, it is possible to know in detail the power that can be consumed by the femto base station 10 according to the state of each PoE line, and to limit the functions. The contents of (degenerate operation) can be subdivided.

  By using the combination table, the processor 11 can read the contents (scale and combination) of the degenerate operation corresponding to the consumable power obtained based on the state of each PoE line from the combination table and determine the contents as the degenerate operation. it can.

<Consideration of connected UE information>
In addition to the combination table, information related to the radio terminal (UE) 40 that is currently connected (accessed) to the femto base station 10 (referred to as “UE information being connected”) is taken as a parameter, so that more detailed degenerate operation can be performed. Control becomes possible. For example, it is possible to perform control such as selecting a combination of degeneration operations that can maintain the connection state of the connected wireless terminal 40 as much as possible. Hereinafter, an example of connected UE information that can be recognized by the femto base station 10 and a control example of degenerate operation will be described.

(A) When the number of users (wireless terminals 40) connected to the femto base station 10 is large In this case, as a degenerate operation, for example, a function unit (function block) that does not affect the number of antennas or communication in use. ) Is given priority. That is, priority is given to maintaining the connection of the wireless terminal 40.

(B) When the number of users (wireless terminals 40) connected to the femto base station 10 is small In this case, for example, a degenerate operation that preferentially decreases the processing speed of the CPU is performed. In other words, an operation is performed in which the wireless quality is maintained while the connection state with the user (wireless terminal 40) is maintained.

  FIG. 7 is a diagram illustrating the relationship between the number of connected UEs indicating the number of radio terminals 40 connected to the femto base station 10 and the operating state of the CPU. FIG. 7 shows a degenerate example of the CPU processing speed depending on the number of UEs. In the example illustrated in FIG. 7, the relationship between the number of CPU operation cores when the number of connected UEs is “20 or more”, “10 to 19”, and “9 or less” and the CPU operation clock is illustrated.

  Specifically, when the number of connected UEs is 20 or more, the CPU has an operation core number of 2 (dual) and is used with an operation clock of 1 GHz. When the number of connected UEs is 10 to 19, the CPU is dual and used with an operation clock of 800 MHz. If the number of connected UEs is 9 or less, the CPU is used with an operation clock having a number of operating cores of 1 (single) and 600 MHz. By performing the operation of the CPU according to the number of connected UEs, the degenerate operation shown in (A) and (B) described above can be performed.

(C) When there are few users (radio terminals 40) far away from the femto base station In this case, a degenerate operation in which a decrease in transmission power is preferentially performed is performed. FIG. 8 is a diagram illustrating the relationship between the maximum path loss amount of the UE (wireless terminal 40) connected to the femto base station 10 and the transmission power.

  Here, the path loss is an RF (radio) propagation loss. The path loss is the difference between the transmission power of the femto base station 10 and the reception power of radio waves from the radio terminal 40 (UE). Usually, the path loss increases as the radio terminal 40 moves away from the femto base station 10. For this reason, the path loss can be used as a parameter indicating the distance between the femto base station 10 and the radio terminal 40.

  In the example shown in FIG. 7, the maximum path loss amount is divided into large, medium, and small classes, and transmission power values corresponding to the respective classes are set. Specifically, when the maximum path loss amount is large (for example, 120 dBm or more), the transmission power is set to 100 mW. Further, when the maximum path loss amount is medium (for example, 110 to 119 dBm), the transmission power is set to 50 mW. Further, when the maximum path loss amount is small (for example, 109 dBm or less), the transmission power is set to 10 mW. As described above, when there is no wireless terminal 40 located away from the femto base station 10, the transmission power is reduced to reduce the power consumption.

The contents of the degenerate operation such as (a) to (d) and (A) to (C) described above are stored in advance in a combination table, for example, so that they can be implemented within the range of consumable power. FIG. 9 shows an example of the data structure of the combination table for degenerate operation. FIG. 9 shows the above-described (a) to (d).
The example of a data structure of the combination table reflecting each degeneracy operation demonstrated by (A)-(C) is shown. In the combination table of FIG. 9, the contents of the degenerate operation based on the connected UE information (number of connected UEs, path loss amount) are incorporated in the combination table shown in FIG. In mounting, for example, both the combination table of FIG. 6 and the combination table of FIG. 9 are mounted. However, only one of the combination table of FIG. 6 and the combination table of FIG. 9 may be implemented.

<Processing flow of the processor>
FIG. 10 is a flowchart illustrating an example of a processing flow of the processor. The process shown in FIG. 10 is started when the processor 11 starts monitoring the voltage abnormality of each PoE line at an appropriate timing (01).

  In 02, the processor 11 determines, for each PoE line, whether or not the voltage supplied from the PoE line (PoE supply voltage) is below the power monitoring threshold. The process 02 is determined, for example, when the processor 11 determines whether or not there is an interrupt notification from each power supply monitoring circuit 263. In 02, when there is no interrupt notification (all PoE lines are normal) (02, No), all the degeneration operations are canceled or the degeneration operation is partially canceled according to the power consumption (10). ). However, when the femto base station 10 is operating in the normal mode at time 02, the normal mode (normal operation) is maintained.

  On the other hand, if the supply voltage from at least one PoE line falls below the power monitoring threshold at 02 (02, Yes (PoE line failure detection)), the process proceeds to 03. In 03, the processor 11 calculates the amount of power that can be used based on the power that can be received from the remaining PoE lines.

  In the next 04, the processor 11 determines whether or not to perform degeneration control using the connected UE information. When degeneration control is not performed (04, No), the process proceeds to 09 and the combination table shown in FIG. 6 is read. Thereafter, the process proceeds to 07.

  On the other hand, when degeneration control using the connected UE information is performed (04, Yes), the process proceeds to 05. In 05, the processor 11 confirms the information of the connected user (wireless terminal 40). Subsequently, the processor 11 reads the combination table shown in FIG. 9 from the flash memory 13.

  In 07, the processor 11 determines the contents (scale and range) of the reduced operation according to the combination table (FIG. 9 or FIG. 6). Then, the processor 11 starts the operation (degenerate operation) in the degenerate operation mode (08).

  In the flowchart shown in FIG. 10, the processes of 04 to 06 may be omitted. Alternatively, the processes 04 and 09 may be omitted.

<Effects of Embodiment>
According to the femto base station 10 described above, when the power supply from the PoE line falls below a predetermined value (power supply monitoring threshold) due to abnormality of the PoE line that receives power supply, the processor 11 The operation in the reduced operation mode in which the ten functions are reduced is started. Thereby, the femto base station 10 can maintain the operation state, that is, continue the operation.

In transition to the degenerate operation mode, the consumable power of the femto base station 10 is calculated, and the contents of the degenerate operation so that the power consumption of the femto base station 10 is within the range of consumable power (
Scale and scope) is determined. As a result, power shortage in the degraded operation mode can be avoided.

  In addition, by storing a combination table of degenerate operations in advance, it is possible to easily calculate the depleted operation mode by calculating the consumable power from the receivable power of the remaining PoE lines excluding the PoE lines whose power supply status is abnormal. It is possible to easily determine the operation contents in the above, that is, the contents of the degenerate operation.

  In addition, the combination table stores in advance the content of the degenerate operation reflecting the connected UE information, so that not only the operating state of the femto base station 10 is maintained, but also the connected wireless terminal 40 (user). Protection (maintenance of connection) can be achieved.

  The configurations of the embodiments described above can be combined as appropriate.

DESCRIPTION OF SYMBOLS 10 ... Femto base station 11 ... Processor 12 ... DRAM memory 13 ... Flash memory 14 ... Hard disk drive 15-19 ... RF part 20-24 ... Transmission / reception antenna

Claims (15)

A communication device that operates with power supplied from a communication line,
Degenerate operation of the communication device including at least one of partial stoppage of the function of the communication device and performance degradation of the function when it is detected that the power supplied from the communication line has fallen to a predetermined range. A communication device including a control device to be started. The communication line includes a plurality of communication lines for supplying power,
The communication apparatus according to claim 1, wherein the control apparatus starts a degenerate operation of the communication apparatus when a decrease in power supplied from at least one of the plurality of communication lines is detected. The control device performs the degenerate operation so that power consumption is within a range of power supplied from the remaining communication lines when a decrease in power supplied from at least one of the plurality of communication lines is detected. The communication device according to claim 1 or 2, wherein the content is determined. The communication device according to any one of claims 1 to 3, wherein the control device reduces transmission power for transmitting a radio signal from an antenna included in the communication device as a degenerate operation of the function. The communication device according to any one of claims 1 to 4, wherein the control device reduces the number of antennas used in the communication device as a reduced operation of the function. The communication device according to any one of claims 1 to 5, wherein the control device reduces the number of wireless terminals that can be connected in parallel to the communication device as a reduced operation of the function. The communication device according to any one of claims 1 to 6, wherein the control device lowers an operation clock of a central processing unit included in the communication device as a reduced operation of the function. The communication device according to any one of claims 1 to 7, wherein the control device reduces the number of cores used by a central processing unit having a multi-core configuration included in the communication device as a reduced operation of the function. 9. The control device according to claim 1, wherein the control device stops one of a first wireless communication method and a second wireless communication method that can be used by the communication device as a reduced operation of the function. 10. Communication equipment. The communication device according to claim 1, wherein the control device stops at least one of a plurality of auxiliary storage devices included in the communication device as a reduced operation of the function. The communication device according to any one of claims 1 to 10, wherein the control device performs a degenerate operation of a function according to information related to a wireless terminal connected to the communication device. The communication device according to claim 11, wherein the control device reduces an operation clock of a central processing unit included in the communication device when the number of wireless terminals connected to the communication device is within a predetermined range. The communication device according to claim 11 or 12, wherein the control device reduces the number of cores used by the central processing unit included in the communication device when the number of wireless terminals connected to the communication device is smaller than the predetermined range. 14. The control device according to claim 11, wherein the control device reduces transmission power for transmitting a radio signal from an antenna included in the communication device according to a distance between the wireless terminal connected to the communication device and the communication device. The communication apparatus according to claim 1. Information indicating each of the consumable power of the communication device according to the power supply state of a plurality of communication lines to which the communication device is supplied with power and the contents of the degenerate operation of the function corresponding to the consumable power is stored. Further includes a storage device,
The control device reads the contents of the degeneration operation corresponding to the consumable power obtained from the power supply states from the plurality of communication lines from the storage device, and starts the degeneration operation with the read contents of the degeneration operation. The communication device according to any one of 1 to 14.

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